Detection of CMB-Cluster Lensing using Polarization Data from SPTpol

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500  deg^{2} survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.8σ. The mean stacked mass of the selected sample is found to be (1.43±0.40)×10^{14}M_{⊙} which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.

1264. Characterization of HIV-Positive Patients with Low-Level Viremia in a Community HIV Clinic Between 2014 and 2018

Background

Low-level viremia (LLV) has been defined as an HIV RNA level detectable by newer generation viral load quantification assays but that is ≤200 copies/mL.Contributing factors may include intermittent low-level releases of virus from existing reservoirs, random laboratory variation and decreased ART adherence.

Methods

This retrospective chart review aimed to characterize patients who developed LLV in a community HIV clinic between 2014 and 2018. LLV was defined as two consecutive detectable HIV RNA measurements ≤200 copies/mL. Possible factors that could be associated with viral rebound (VR), defined as an HIV RNA >200 copies/mL, were evaluated by using multivariate logistic regression.

Results

Of a total of 666 patients, 111 met criteria for LLV. Seventy-seven were male and 34 were female. The majority were African American (85.6%) with Hispanic and white accounting for 5.4% each. Fifty-five percent were heterosexual and 31.5% were men that have sex with men. Analyzing CD4 counts at the moment or just prior to the development of LLV, 42 of them (37.8%) had a CD4 between 501 and 800 cells/mm³, 25 (22.5%) between 200 and 500 cells/mm3 and only 3.6% had CD4 counts <200 cells/mm³. The majority (60.3%) were on integrase inhibitors (INSTI). Of the 111 patients, only 59 of them had at least 1-year follow-up post LLV. Those who were followed for less than 12 months post-LLV were not included in the statistical analysis to try and find potential factors associated with VR post LLV. Twelve (20.3%) of the 59 developed VR. HIV RNA levels between 51 and 100 copies/mL and 101 and 200 copies/mL were associated with higher odds of VR (OR 3.77 95% CI 0.37–38.77, 3.09 95% CI 0.27–35.88, respectively). Patients with STIs, heterosexuals and those on INSTI were also associated with higher odds of VR (OR 1.48 95% CI 0.12–18.5, 3.13 95% CI 0.75–13.03 and 1.61 95% CI 0.35–7.38, respectively). These results did not achieve statistical significance.

Conclusion

This community HIV clinic has a low prevalence of LLV. Most of the patients did not develop VR. Although some clinical factors were found to be associated with viral rebound in patients with LLV, the associations did not achieve statistical significance. LLV is a phenomenon that requires further research, specifically regarding predictors of VR, particularly now in the INSTI era.

Disclosures

All authors: No reported disclosures.

Cosmological Constraints from Multiple Probes in the Dark Energy Survey

The combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured 207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy clustering. Here we present combined results from these probes, deriving constraints on the equation of state, w, of dark energy and its energy density in the Universe. Independently of other experiments, such as those that measure the cosmic microwave background, the probes from this single photometric survey rule out a Universe with no dark energy, finding w=-0.80_{-0.11}^{+0.09}. The geometry is shown to be consistent with a spatially flat Universe, and we obtain a constraint on the baryon density of Ω_{b}=0.069_{-0.012}^{+0.009} that is independent of early Universe measurements. These results demonstrate the potential power of large multiprobe photometric surveys and pave the way for order of magnitude advances in our constraints on properties of dark energy and cosmology over the next decade.

Building a network for multicenter, prospective research of central nervous system infections in South America: Process and lessons learned

Multicenter collaborative networks are essential for advancing research and improving clinical care for a variety of conditions. Research networks are particularly important for central nervous system infections, which remain difficult to study due to their sporadic occurrence and requirement for collection and testing of cerebrospinal fluid. Establishment of long-term research networks in resource-limited areas also facilitates diagnostic capacity building, surveillance for emerging pathogens, and provision of appropriate treatment where needed. We review our experience developing a research network for encephalitis among twelve hospitals in five Peruvian cities since 2009. We provide practical suggestions to aid other groups interested in advancing research on central nervous system infections in resource-limited areas.

Comparison of neutron organ and effective dose coefficients for PIMAL stylized phantom in bent postures in standard irradiation geometries

Neutron dose coefficients for standard irradiation geometries have been reported in International Commission on Radiological Protection (ICRP) Publication 116 for the ICRP Publication 110 adult reference phantoms. In the present work, organ and effective dose coefficients have been calculated for a receptor in both upright and articulated (bent) postures representing more realistic working postures exposed to a mono-energetic neutron radiation field. This work builds upon prior work by Dewji and co-workers comparing upright and bent postures for exposure to mono-energetic photon fields. Simulations were conducted using the Oak Ridge National Laboratory's articulated stylized adult phantom, "Phantom wIth Moving Arms and Legs" (PIMAL) software package, and the Monte Carlo N-Particle (MCNP) version 6.1.1 radiation transport code. Organ doses were compared for the upright and bent (45° and 90°) phantom postures for neutron energies ranging from 1 × 10^- 9 to 20 MeV for the ICRP Publication 116 external exposure geometries-antero-posterior (AP), postero-anterior (PA), and left and right lateral (LLAT, RLAT). Using both male and female phantoms, effective dose coefficients were computed using ICRP Publication 103 methodology. The resulting coefficients for articulated phantoms were compared to those of the upright phantom. Computed organ and effective dose coefficients are discussed as a function of neutron energy, phantom posture, and source irradiation geometry. For example, it is shown here that for the AP and PA irradiation geometries, the differences in the organ coefficients between the upright and bent posture become more pronounced with increasing bending angle. In the AP geometry, the brain dose coefficients are expectedly higher in the bent postures than in the upright posture, while all other organs have lower dose coefficients, with the thyroid showing the greatest difference. Overall, the effective dose estimated for the upright phantom is more conservative than that for the articulated phantom, which may have ramifications in the estimation or reconstruction of radiation doses.

Genetic Mapping of Quantitative Trait Loci for Grain Yield under Drought in Rice under Controlled Greenhouse Conditions

Drought stress is a constant threat to rice production worldwide. Most modern rice cultivars are sensitive to drought, and the effect is severe at the reproductive stage. Conventional breeding for drought resistant (DR) rice varieties is slow and limited due to the quantitative nature of the DR traits. Identification of genes (QTLs)/markers associated with DR traits is a prerequisite for marker-assisted breeding. Grain yield is the most important trait and to this end drought yield QTLs have been identified under field conditions. The present study reports identification of drought yield QTLs under controlled conditions without confounding effects of other factors prevalent under natural conditions. A linkage map covering 1,781.5 cM with an average resolution of 9.76 cM was constructed using an F₂ population from a cross between two Japonica cultivars, Cocodrie (drought sensitive) and Vandana (drought tolerant) with 213 markers distributed over 12 rice chromosomes. A subset of 59 markers (22 genic SSRs and 37 SNPs) derived from the transcriptome of the parents were also placed in the map. Single marker analysis using 187 F_{2 : 3} progeny identified 6 markers distributed on chromosomes 1, 5, and 8 to be associated with grain yield under drought (GYD). Composite interval mapping identified six genomic regions/quantitative trait loci (QTL) on chromosome 1, 5, 8, and 9 to be associated with GYD. QTLs located on chromosome 1 (qGYD1.2, qGYD1.3), chromosome 5 (qGYD5.1) and chromosome 8 (qGYD8.1) were contributed by Vandana alleles, whereas the QTLs, qGYD1.1 and qQYD9.1 were contributed by Cocodrie alelles. The additive positive phenotypic variance explained by the QTLs ranged from 30.0 to 34.0%. Candidate genes annotation within QTLs suggested the role of transcription factors and genes involved in osmotic potential regulation through catalytic/metabolic pathways in drought tolerance mechanism contributing to yield.

Distinguishing Petroleum (Crude Oil and Fuel) From Smoke Exposure within Populations Based on the Relative Blood Levels of Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX), Styrene and 2,5-Dimethylfuran by Pattern Recognition Using Artificial Neural Networks

Studies of exposure to petroleum (crude oil/fuel) often involve monitoring benzene, toluene, ethylbenzene, xylenes (BTEX), and styrene (BTEXS) because of their toxicity and gas-phase prevalence, where exposure is typically by inhalation. However, BTEXS levels in the general U.S. population are primarily from exposure to tobacco smoke, where smokers have blood levels on average up to eight times higher than nonsmokers. This work describes a method using partition theory and artificial neural network (ANN) pattern recognition to classify exposure source based on relative BTEXS and 2,5-dimethylfuran blood levels. A method using surrogate signatures to train the ANN was validated by comparing blood levels among cigarette smokers from the National Health and Nutrition Examination Survey (NHANES) with BTEXS and 2,5-dimethylfuran signatures derived from the smoke of machine-smoked cigarettes. Classification agreement for an ANN model trained with relative VOC levels was up to 99.8% for nonsmokers and 100.0% for smokers. As such, because there is limited blood level data on individuals exposed to crude oil/fuel, only surrogate signatures derived from crude oil and fuel were used for training the ANN. For the 2007-2008 NHANES data, the ANN model assigned 7 out of 1998 specimens (0.35%) and for the 2013-2014 NHANES data 12 out of 2906 specimens (0.41%) to the crude oil/fuel signature category.

Community-Based Accompaniment with Supervised Antiretrovirals for HIV-Positive Adults in Peru: A Cluster-Randomized Trial

We conducted a cluster-randomized trial to estimate effects of directly observed combination antiretroviral therapy (DOT-cART) on retention with viral suppression among HIV-positive adults in Peru. We randomly allocated facilities to receive the 12-month intervention plus the standard of care, including adherence support provided through accompaniment. In the intervention arm, health workers supervised doses, twice daily, and accompanied patients to appointments. Among 356 patients, intention-to-treat analyses showed no statistically significant benefit of DOT, relative to no-DOT, at 12 or 24 months (adjusted probability of primary outcome: 0.81 vs. 0.73 and 0.76 vs. 0.68, respectively). A statistically significant benefit of DOT was found in per-protocol and as-treated analyses at 12 months (0.83 for DOT vs. 0.73 for no DOT, p value: 0.02 per-protocol, 0.01 as-treated), but not 24 months. Rates of retention with viral suppression were high in both arms. Among adults receiving robust adherence support, the added effect of time-limited DOT, if any, is small-to-moderate.